Sheet transfer device



March 5, 1957 Filed May 12, 1953 R. J. VAN SCHIE 2,783,872 SHEET TRANSFER DEVICE 4 Shee tS-Sheet 1 iii-1;;

INVENTOR! Rofier/ J Van Jc/N'e March 5, 1957 R. J. VAN SCHIE 2,783,872

SHEET TRANSFER DEVICE Filed May 12, 1953 4 Sheets-Sheet Z5 Ill] Z6 4 Z? & 24 Z ATTORNEY.

March 5, 1957 R. J. VAN SCHIE 8 I SHEET TRANSFER DEVICE Filed May 12, 1953 4 SheetsSheet 3 v INVENTOR. Kafier/ J Van icfi/z [WWW Arron/E).

' March 1957 R. J. VAN SCHIE 2,783,872

SHEET TRANSFER DEVICE Filed May 12, -1953 4 Sheets-Sheet 4 INVENTOR. Aoer/ J Van Jcfi/e ATTORNEY.

2,783,872 7 Patented Mar. 5, 1957 SHEET TRANSFER DEVICE Robert J. Van Schie, Hollywood, Calif. Application May 12, 1953, Serial No. 354,481

21 Claims. (Cl. 198-218) This invention relates to improvements in a sheet transfor device.

The principal objects of this invention are:

First, to provide a device for rapidly and accurately transferring stifi sheets such as sheets of metal between aligned work positions.

Second, to provide a device which can be used to automatically advance metal sheets progressively along a line of work stations such as the beds of a series of forming presses.

Third, to provide a sheet transfer device that will extract a sheet of metal from the bed of a forming press and advance the sheet to a second press or a work discharge station without interfering with the operation or" the press.

Other objects and advantages of the invention will be apparent from a consideration of the following description and claims. The drawings, of which there are four sheets, illustrate two forms of the invention.

Fig. 1 is a side elevational view partially broken away of a first form of the transfer device operatively associated with a plurality of work supports or stations.

Fig. 2 is a fragmentary enlarged side elevational view of one portion of the transfer device shown in Fig. 1.

Fig. 3 is a fragmentary plan view of the structure shown in Fig. 2.

Fig. 4- is a fragmentary transverse vertical cross sectional view taken along the plane of the line 4-4 in Fig. 3.

Fig. 5 is a fragmentary elevational view partially broken away from the inside of the transfer device taken along the plane of the line 55 in Fig. 3.

Fig. 6 is a fragmentary elevational view showing a portion of the structure shown in Fig. 5 at an initially actuated position of the device.

Fig. 7 is a fragmentary elevational view similar to Fig. 6 showing the structure in a further actuated position.

Fig. 8 is a transverse cross sectional view showing one of the jaws and rockers in the position shown in Fig. 7.

Fig. 9 is a fragmentary elevational view showing the structure in Figs. 5 to 7 in a still further actuated position. 1

Fig. 10 is a fragmentary side elevational view partially broken away of a modified form of the feeding device.

Fig. 11 is a fragmentary transverse cross sectional view taken along the plane of the line 11-41 in Fig. 10.

The sheet transfer device is designed primarily to advance large metal sheets successively along a line of press beds where the sheets may be progressively formed or shaped. In Fig. l the reference numerals 1, 2 and 3 represent the beds or lower die supports of sheet metal.

presses. The frames and upper dies of the presses are not illustrated but it will be understood that the transfer mechanism to be described extends through the openings of the press frames. The transfer structure comprises generally a pair of longitudinally extending guide rails 4 that extend through the openings of the several presses and alongside of the press beds. The guide rails are supported on suitable legs 5.

Slidably supported on the rails 4 is a carriage 6 and the carriage is provided with longitudinally spaced sets of sheet transfer mechanisms indicated generally at 7A and 7B. The mechanisms 7A and 7B are spaced along the carriage by a distance equal to the spacing of the press beds 1, 2 and 3 so that adjacent transfer mechanisms may be located over adjacent beds. A carriage reciprocating structure in the form of a fluid operated cylinder 8 and piston 9 is supported at the rear end of the guide rails and the piston rod 10 connects to the rear end of the carriage to advance the same to the left, as viewed in the drawings, and to thereafter retract the carriage to starting position. The transfer mechanisms 7A and 7B are identical and a description of one set will illustrate the operation of the device. It will be appreciated that the number of transfer mechanisms may be increased or decreased depending upon the number of the press beds between which the transfer device is designed to operate.

As is more particularly illustrated in Figs. 2 to 5, each transfer mechanism includes a pair of rockers 11 and 12 pivotally supported at 13 and 14 on each side of the carriage 6. The carriage 6 includes side bars 15 that slide on the side rails 4 and the side bars are connected by a cross bar 16 at the rear end of the carriage. The rockers 11 and 12 have angularly disposed lower edges 17 and 18 that are respectively disposed to support the rockers in downwardly and rearwardly inclined position as in Figs. 1 to 6 or in upright position as in Figs. 7 and 8.

The swinging ends of the rockers 11 and 12 carry pins 19 that project inwardly from the sides of the carriage. Links 20 connect the rockers of each pair and when multiple transfer mechanism are employed, interconnecting links such as the curved links 21 are provided so that all rockers on each side of the carriage are interconnected. Coil springs 22 disposed around the outer ends of the pins 19 are compressed between the links 20 and thrust washers 23 to bias the pins outwardly of the carriage.

The inwardly projecting ends of the pins 19 carry depending jaw supporting arms 24 having the laterally in- Wardly facing jaws 25 on their lower ends. The jaw supporting arms of each transfer mechanism on each side thereof are connected by tie bars 26 pivotally supported by the screws 27. Swingably supported by the pins 19 between the rockers 11 or 12 and the jaw support ing arms 24 are actuating levers 28. The springs 22 function to draw the arms 24 and levers 28 outwardly in abutting engagement with the inner sides of the rockers. All of the actuating levers 28 on either side of the carriage 6 are interconnected by longitudinally extending actuating bars 29 that are pivotally connected to the lower ends of the levers by pins 30.

As is most clearly illustrated in Figs. 3, 4 and 8, the adjacent ends of each rocket and its associated jaw supporting arm and actuating lever are cooperatively cammed axially with respect to the connecting pin 19. The rocker has an axially retracted recess 31 positioned to receive the axially extended lift 32 of the actuating lever when the rocker is in retracted inclined position and when the lever is in depending and rearwardly rotated position as is shown in Figs. 3 and 4. The upper end of the jaw supporting arm 24 is similarly provided with a recessed cam surface 33 receiving an oppositely advanced surface 34 on the lever. When the levers 28 are rotated or swung forwardly as in Figs. 6, 7 and 8, the lifts 32 and 34 of the cam surfaces on the actuating lever are brought into mating engagement with lift surfaces 35 and 36 on the rocker and jaw supporting arm, respectively. As is readily apparent in Fig.

8, the engagement of the lift surfaces of the several cams causes the jaw supporting arm- 24 to be moved inwardly from the sides of the carriage into a position where the jaw 25 will engage and grip the edge of a metal or other sheet 37 resting on one of the work supports.

The longitudinally extending actuating bars 29 project to the rear of the carriage 6 and, as is illustrated in Fig. l, are adapted to abut against and coact with stops 38 mounted on the side rails 4. Thus with the several rockers in the position illustrated in Figs. 1, 2 and 5, rearward retracting motion of the carriage will first engage the actuating bars 29 with the stops 38 causing the actuating bars to move forwardly with respect to the carriage as shown in Fig. 6. This motion of the actuating bars causes the actuating levers and their cam surfaces to move the jaws 25 inwardly to grip the edge of a sheet supported on one of the work supports. Continued retraction of the carriage and relatively forward movement of the actuating bars 29 and levers 28 brings the pivots 3t above the line between the rocker pivots 13 and the pins 19. The actuating bars 29 thus exert an erecting force on the pins 19 and levers 23 and the rockers move to the upright position shown in Figs. 7 and 8. The sheet engaged by the jaws 25 is thus elevated above the work support from which it has been taken.

Subsequent advancing motion of the piston rod 10 and carriage 6 advances each transfer mechanism from one press bed to the next. In order to release and deposit the advance sheets in their advanced positions, a forward stop 39 is carried at the forward end of the side rails to abut against the upstanding rocker 11 on the leading transfer mechanism. The final increment of forward motion of the carriage thus causes the rockers 11 and 12 to be tilted rearwardly from their supporting surfaces 18 to the supporting surfaces 17. The rearward rotation of the rockers brings the recesses 31 and 33 of the cam surfaces into engagement with the lifts 32 and 34 on the actuating levers and the jaw supporting arms 24 are drawn outwardly by the springs 22 to deposit the sheet in its advanced position. Should the levers 28 tend to stay in forward tilted position, the impact of the rockers on the carriage and the inertia of the levers and bars 29 will return the levers to depending jaw retracting position.

The modified form of transfer device shown in Figs. 10 and 11 incorporates a slightly different mechanical action for moving the jaw supporting arms inwardly and outwardly with respect to the carriage and further provides means for swinging the entire carriage and a sheet car-- ried thereby from horizontal to vertical position so that the sheet may be discharged in vertical position to an off-feeding conveyor or to other mechanisms as may be desired.

The rockers 11 remain the same as in the first form of the invention but the side bars 40 of the carriage are provided with laterally projecting pins or studs 41 at their leading end. The ends of the side bars 40 are further convexly curved as at 42 so that the side bars and carriage may rock upwardly on the side rails 43 without being disengaged from the side rails. Pivotally supported on the side rails at the forward ends thereof are tilting arms 44. The arms are pivotally supported at 45 and are slotted at 46 to receive the pins 41. A fluid operated cylinder 47 has its piston rod connected to the tilting arm at 48 and functions to swing the arms and the carriage to the upright position indicated by the dotted lines at 49. A stop 5% carried at the forward ends of the side rails functions to strike the forward rockers 11 and collapse the rockers upwardly toward the side bars 40 of the upright carriage. In order to permit the carriage to be disengaged from its reciprocating mechanism, the rear end of the carriage is provided with upstanding arms 52 that are downwardly and rearwardly slotted as at 53. The slots 53 releasably receive a crossbar 54 on the forward end of the carriage reciprocating piston rod 55.

As is most readily apparent in Fig. ll, the pins 56 PIG.- icctins l l y rom the ro ker 11 a oppo ite sc e threaded as at 57 and 58. The threads 57 engage the upper end of the rocker 11 and the threads 58 engage the upper end or" the jaw support arm 59. The actuating lever 69 is secured to the mid section of the pin 5d as by a setscrew 61. Thus by rotation of the actuating lever 6t and the pin 56, the pin maybe caused to screw itself outwardly with respect to the rocker 11 while the jaw supporting arm 59 is drawn further outwardly on the threads 58 to retract the jaw 62 from the work. Reverse rotation of the lever and pin move the pin and jaw supporting arm inwardly into work gripping position. As in the previous form of the transfer device, the rockers are connected by a link 63 and the jaw supporting arms are connected by a tie bar 64. The actuating bar 65 consects tte actuating levers 60 and projects rearwardly for coaction with a fixed stop at the rear end of the side rails 43.

it is pointed out that the cam surfaces 31 to 34, which advance the first form of the jaw supporting arms, and the screw threads 57 and 53, which advance the second form of the jaw supporting arms, may be limited to act solely on one side or the other of the actuating lever in cooperation with either the rockers or the jaw supporting arms. However, the double cams and threads illustrated provide greater motion for the jaws with a minimum of motion of the actuating levers. When handling extra large sheets that might buckle under the pressure of the opposed jaws 25 a stop 66 may be adjustably mounted on an arm 67 that projects over the center of the sheet from one of the tie rods 26 (see Fig. 3). The stop is adjusted to permit slight upward bow in the sheet but to prevent complete collapse of the sheet.

Other modifications or variations of the structures illustrated may be made without departing from the spirit of the invention as defined in the following claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. A machine for advancing still metal sheets along aligned and equally spaced work supports comprising, guide rails forming slideways extending between and along opposite sides of said supports, a carriage slidable on said ways and extending a distance equal to the length of two adjacent supports and the space therebetween, sets of rockers mounted on said carriage and spaced therealong equally to the spacing of said supports, each set of rockers comprising a longitudinally spaced pair on opposite sides of the carriage with links connecting the rockers of each pair, said rockers having pivotal connections to said carriage and having angularly disposed adjacent edges engageable with said carriage to support the rockers alternatively in upright and rearwardly inclined position relative to the advancing motion of said carriage, pins projecting inwardly of the swinging ends of said rockers, springs coacting between the outer ends of said pins and said links and acting to bias said pins outwardly, jaw supporting arms depending from the inner ends of said pins and having inwardly facing sheet engaging jaws on their lower ends, tie bars connecting the arms on each pair of rockers, actuating levers pivoted on said pins between said rockers and said arms, coacting cam surfaces formed on the adjacent ends of said levers and arms and rockers whereby rearward oscillation of said levers brings the recessed portions of the cam surfaces into engagement and permits said springs to retract said arms outwardly with respect to said supports, actuating bars connecting the levers on each side of said carriage and projecting beyond the rear end thereof, stops coacting with the rear ends of actuating bars at the end of the retracting stroke of said carriage whereby retraction of said carriage first moves said levers relatively forwardly to engage the lifts of said cam surfaces and force said arms and jaws inwardly to sheet engaging position, and to thereafter apply an erecting force to said rockers to elevate the same, other stops at the other end of said ways coacting with the upright ends of the rockers at the leading end of said carriage to tilt said rockers rearwardly to lowered position at the end of the advancing motion of said carriage, and a drive element connected to reciprocate said carriage over adjacent work supports. 7

2. A machine for advancing stiff metal sheets along aligned and equally spaced work supports comprising, guide rails forming slideways extending between and along opposite sides of said supports, a carriage slidable on said ways and extending a distance equal to the length of two adjacent supports and the space therebetween, sets of rockers mounted on said carriage and spaced there along equally to the spacing of said supports, each set of rockers comprising a longitudinally spaced pair on opposite sides of the carriage with links connecting the rockers of each pair, said rockers having pivotal connections to said carriage and having angularly disposed adjacent edges engageable with said carriage to support the rockers alternatively in upright and rearwardly inclined position relative to the advancing motion of said carriage, pins projecting inwardly of the swinging ends of said rockers, springs acting to bias said pins outwardly, jaw supporting arms depending from the inner ends of said pins and having inwardly facing sheet engaging jaws on their lower ends, tie bars connecting the arms on each pair of rockers, actuating levers pivoted on said pins between said rockers and said arms, coacting cam surfaces formed on the adjacent ends of said levers and arms and rockers whereby rearward oscillation of said levers brings the recessed portions of the cam surfaces into engagement and permits said springs to retract said arms outwardly with respect to said supports, actuating bars connecting the levers on each side of said carriage, stops coacting with actuating bars at the end of the retracting stroke of said carriage whereby retraction of said carriage first moves said levers relatively forwardly to engage the lifts of said cam surfaces and force said arms and jaws inwardly to sheet engaging position, and to thereafter apply an erecting force to said rockers to elevate the same, other stops coacting with the upright ends of the rockers at the leading end of said carriage to tilt said rockers rearwardly to lowered position at the end of the advancing motion of said carriage, and a drive element connected to reciprocate said carriage over adjacent work supports.

3. A machine for advancing stiff sheets along aligned work supports located on equally spaced centers comprising guide rolls forming slideways extending between and along, opposite sides of said supports, a carriage slidable on said ways and extending a distance equal to twice the length of the space between two centers, sets of rockers mounted on said carriage and spaced therealong equally to the spacing of said centers, each set of rockers comprising rockers on each side of said carriage and including a longitudinally spaced pair on one side of the carriage with links connecting the rockers of each pair, said rockers having pivotal connections to said carriage and having angularly disposed adjacent edges engageable with said carriage to support the rockers alternatively in upright and rearwardly inclined position relative to the advancing motion of said carriage, pins projecting inwardly of the swinging ends of said rockers, springs acting to bias said pins outwardly, jaw supporting arms depending from the inner ends of said pins and having inwardly facing sheet engaging jaws on their lower ends, tie bars connecting the arms on each pair of rockers, actuating levers pivoted on said pins between said rockers and said arms, coacting cam surfaces formed on the adjacent ends of said levers and arms whereby rearward oscillation of said levers brings the recessed portions of the cam surfaces into engagement and permits said springs to retract said arms outwardly with respect to said supports, actuating bars connecting the levers on each side of said carriage,'stops coacting with said actuating bars at the end of the retracting stroke of said carriage whereby retraction of said carriage first moves said levers relatively forwardly to engage the lifts of said cam surfaces and force said arms and jaws inwardly to sheet engaging position, and to thereafter apply an erecting force to said rockers to elevate the same,

and other stops coacting with the upright ends of the rockers at the leading end of said carriage to tilt said rockers rearwardly to lowered position at the end of the advancing motion of said carriage.

4. A machine for advancing stilf' sheets along aligned work supports located on equally spaced centers comprising, guide rails forming slideways extending between and along opposite sides of said supports, a carriage slidable on said ways and extending a distance equal to twice the length of the space between two centers, sets of rockers mounted on said carriage and spaced therealong equally to the spacing of said centers, each set of rockers comprising rockers on each side of said carriage and including a longitudinally spaced pair on one side of the carriage with links connecting the rockers of each pair, said rockers having pivotal connections to said carriage and having angularly disposed adjacent edges engageable with said carriage to support the rockers portions of the cam surfaces into engagement and permits said springs to retract said arms outwardly with.

respect to said supports, actuating bars connecting the levers on each side of said carriage, stops coacting with said actuating bars at the end of the retracting stroke of said carriage whereby retraction of said carriage first moves said levers relatively forwardly to engage the lifts of said cam surfaces and force said arms and jaws inwardly to sheet engaging position, and to thereafter apply an erecting force to said rockers to elevate the same, and other stops coacting with the upright ends of the rockers at the leading end of said carriage to tilt said rockers rearwardly to lowered position at the end of the.advancing motion of said carriage.

5. A machine for advancing stilt sheets along aligned work supports comprising, slideways extending between and along opposite sides of said supports, a carriage slidable on said ways and adapted to extend simultaneously over adjacent supports, sets of rockers mounted on said carriage and spaced therealong to register with two of said supports, each set of rockers comprising a longitudinally spaced pair on opposite sides of the carriage, links connecting the rockers on each side of the carriage, said rockers having pivotal connections to said carriage and having angularly disposed stops engageable with said carriage to support the rockers alternatively in upright and rearwardly inclined position relative to the advancing motion of said carriage, pins projecting inwardly of the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing sheet engaging jaws on their lower ends, springs biasing said arms outwardly toward said rockers, tie bars connecting the arms on each pair of rockers, actuating levers pivoted on said pins between said rockers and said arms, cam surfaces formed on the ends of said levers and coacting with said arms and rockers whereby rearward oscillation of said levers permits said springs to retract said arms outwardly with respect to said supports, actuating bars connecting the levers on each side of said carriage, stops coacting with said actuating bars at the end of the retracting stroke of said carriage whereby retraction of said carriage first moves said levers relatively forwardly to cause said camsurfaees to force said arms and jaws inwardly to sheet engaging position, and to thereafter apply an erecting force to said rockers to elevate the same, other stops coacting with the upright ends of the rockers at the leading end of said carriage to tilt said rockers rearwardly to lowered position at the end of the advancing motion of said carriage, and a drive element connected to reciprocate said carriage over adjacent work supports.

6. A machine for advancing stiff sheets along aligned work supports comprising slideways extending between and along opposite sides of said supports, a carriage slidable on said ways and adapted to extend simultaneously over adjacent supports, sets of rockers mounted on said carriage and spaced therealong to register with two of said supports, each set of rockers comprising a longitudinally spaced pair on opposite sides of the carriage, links connecting the rockers on each side of the carriage, said rockers having pivotal connections to said carriage and having angularly disposed stops engageable with said carriage to support the rockers alternatively in upright and rearwardly inclined position relative to the advancing motion of said carriage, pins projecting inwardly of the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing sheet engaging jaws on their lower ends, springs biasing said arms outwardly toward said rockers, actuating levers pivoted on said pins between said rockers and said arms, cam surfaces formed on the ends of said levers and eoacting with said arms and rockers whereby rearward oscillation of said levers permits said springs to retract said arms outwardly with respect to said supports, actuating bars connecting the levers on each side of said carriage, stops coacting with said actuating bars at the end of the retracting stroke of said carriage whereby retraction of said carriage first: moves said lever relatively forwardly to cause said cam surfaces to force said arms and jaws inwardly to sheet engaging position, and to thereafter apply an erecting force to said rockers to elevate the same, other stops coacting with the upright ends of the rockers at the leading end of said carriage to tilt said rockers rearwardly to lowered position at the end of the advancing motion of said carriage, and a drive element connected to reciprocate said carriage over adjacent work supports.

7. A machine for advancing still sheets along aligned work supports comprising guide rails forming slideways extending between and along opposite sides of said supports, a carriage slidable on said ways, a longitudinally spaced pair of rockers on opposite sides of the carriage with links connecting the rockers of each pair, said rockers having pivotal connections to said carriage and having angularly disposed adjacent edges engageable with said carriage to support the rockers alternatively in upright and rcarwardly inclined position relative to the advancing motion of said carriage, pins projecting inwardly of the swinging ends of said rockers, springs coacting between the outer ends of said pins and said links and acting to bias said pins outwardly, jaw supporting arms depending from the inner ends of said pins and having inwardly facing sheet engaging jaws on their lower ends, tie bars connecting the arms on each pair of rockers, actuating levers pivoted on said pins between said rockers and said arms, coa'cting cam surfaces formed on the adjacent ends of said levers and arms and rockers whereby rearward oscillation of said levers brings the recessed portions of the cam surfaces into engagement and permits said springs to retract said arms outwardly with respect to said supports, actuating bars connecting the levers on each side of said carriage and projecting beyond the rear end thereof, stops coacting with the rear ends of actuating bars at the end of the retracting stroke of said carriage whereby retraction of said carriage first moves said levers relatively forwardly to engage the lifts of on each side of said carriage,

said cam surfaces and force said arms and jaws inwardly to sheet engaging position, and to thereafter apply an erecting force to said rockers to'elevate the same, other stops at the other end of said ways coacting with the upright ends of the rockers at the leading end of said carriage to tilt said rockers rearwardly to lowered position at the end of the advancing motion of said carriage, and a drive element connected to reciprocate said carriage over said work supports.

8. A machine for advancing stiff sheets along aligned w rk supports comprising guide rails forming slideways extending between and along opposite sides of said supports, a carriage slidablc on said ways, a longitudinally spaced pair of rockers on opposite sides of the carriage with links connecting the rockers of each pair, said rockers having pivotal connections to said carriage and having angularly disposed adjacent edges engageable with said carriage to support the rockers alternatively in upright and rearwardly inclined position relative to the advancing motionof said carriage, pins projecting inwardly of the swinging ends of said rockers, springs acting to bias said pins outwardly, jaw supporting arms depending from the inner ends of said pins and having inwardly facing sheet engaging jaws on their lower ends, actuating levers pivoted on said pins between said rockers and said arms, coacting cam surfaces formed on the adjacent ends of said levers and arms and rockers whereby rearward oscillation of said levers brings the recessed portions of the cam surfaces into engagement and permits said springs to retract said arms outwardly with respect to said supports, actuating bars connecting the levers on each side of said carriage, stops coacting with the actuating bars at the end of the retracting stroke of said carriage whereby retraction of said carriage first moves said levers relatively forwardly to engage the lifts of said cam surfaces and force said arms and jaws inwardly to sheet engaging position, and to thereafter apply an erecting force to said rockers to elevate the same, other stops at the other end of said ways coacting with the upright rockers at the leading end of said carriage to tilt said rockers rearwardly to lowered position at the end of the advancing motion of said carriage, and a drive element connected to reciprocate said carriage over said work supports.

9. A sheet transfer device comprising, a carriage reciprocable between two stations, a pair of rockers pivotally supported on each side of said carriage and having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, links connecting the rockers on each side of said carriage, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers swingably supported by said pins between said rockers and said arms and depending therebetween, coaeting cam surfaces formed on said levers, said arms and said rockers and adapted to move said arms and jaws inwardly when the lifts of the cam surfaces are engaged, actuating bars connected to the levers on each side of said carriage, springs biasing said arms outwardly of said carriage, stops positioned to eoact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers to engage the lifts of said cam surfaces and to thereafter apply an erecting force to said rockers, and other stops coacting with the elevated ends of said rockers at the end of the advancing stroke of said carriage to collapse said rockers to inclined position.

10. A sheet transfer device comprising, a carriage reciprocable between two stations, a pair of rockers pivotally supported on each side of said carriage and having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, links connecting the rockers pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers swingably supported by said pins between said rockers and said arms, coacting cam surfaces formed on said levers and said rockers and adapted to move said arms and jaws inwardly when the lifts of the cam surfaces are engaged, actuating bars connected to the levers on each side of said carriage, springs biasing said arms outwardly of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers to engage the lifts of said cam surfaces and to thereafter apply an erecting force to said rockers, and at the end of the advancing stroke of said carriage to collapse said rocker to inclined position.

11. A sheet transfer device comprising, a carriage reciprocable between two stations, a pair of rockers pivotally supported at longitudinally spaced points on one side of said carriage, another rocker pivotally supported on the other side of the carriage, said rockers having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, links connecting the rockers on said one side of said carriage, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers swingably supported by said pins between said rockers and said arms and depending therebetween, coacting cam surfaces formed on said levers, said arms and said rockers and adapted to move said arms and jaws inwardly when the lifts of the cam surfaces are engaged, actuating bars connected to the levers on each side of said carriage, springs biasing said arms outwardly of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers to engage the lifts of said cam surfaces and to thereafter apply an erecting force to said rockers, and other stops coacting with the elevated ends of said rockers at the end of the advancing stroke of said carriage to collapse said rockers to inclined position.

12. A sheet transfer device comprising, a carriage reciprocable between two stations, a pair of rockers pivotally supported at longitudinally spaced points on one side of said carriage, another rocker pivotally supported on the other side of the carriage, said rockers having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, links connecting the rockers on said one side of said carriage, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers swingably supported by said pins between said rockers and said arms and depending therebetween, coacting cam surfaces formed on said levers and said rockers and adapted to move said arms and jaws inwardly when the lifts of the cam surfaces are engaged, actuating bars connected to the levers on each side of said carriage, springs biasing said arms outwardly of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers to engage the lifts of said cam surfaces and to thereafter apply an erecting force to said rockers, and other stops coacting with said rockers at the end of the advancing stroke of said carriage to collapse said rockers to inclined position.

13. A sheet transfer device comprising, a carriage reciprocable between two stations, a pair of rockers pivotally supported on each side of said carriage and having angularly disposed stops engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, links connecting the rockers on each side of said carriage, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms t 10 depending from the inner ends of said pinsand having inwardly facing jaws on their lower ends, levers swingably supported by said pins between said rockers and said arms, cam surfaces including threads formed on said pins and rotatable with said levers, said cam surfaces engaging said arms and said rockers to move said arms and jaws inwardly when said levers are swung forwardly with respect to said carriage, actuating bars connected to the levers on each side of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers forwardly to move said arms and jaws inwardly and to thereafter apply an erecting force to said rockers, and to coact with said rockers at the end of the advancing stroke of said carriage to collapse said rockers to inclined position. v

14. A sheet transfer device comprising, a carriage rcciprocable between two stations, a pair of rockers pivotally supported on each side of said carriage and having angularly disposed stops engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, links connecting the rockers on each side of said carriage, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers swingably supported by said pins between said rockers and said arms, cam surfaces rotatable with said levers, said cam surfaces engaging said arms and said rockers to move said arms and jaws inwardly when said levers are swung forwardly with respect to said carriage, actuating bars connected to the levers on each side of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers forwardly to move said arms and jaws inwardly and to thereafter apply'an erecting force to said rockers, and to coact with said rockers at the end of the advancing stroke of said carriage to collapse said rockers to inclined position.

15. A sheet transfer device comprising, a carriage reciprocable between two stations, a pair of rockers pivotally supported on each side of said carriage and having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, links connecting the rockers on each side of said carriage, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers connected to and swingably supported by said pins between said rockers and said arms and depending there between, threads formed on said levers and engaging said arms and said rockers and adapted to move said arms and jaws inwardly when said levers are swung forwardly with respect to said carriage, actuating bars connected to the levers on each side of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers forwardly and to thereafter apply an erecting force to said rockers, and coacting with said rockers at the end of the advancing stroke of said carriage to collapse said rocker to inclined position.

16. A sheet transfer device comprising, a carriage reciprocable between two stations, rockers pivotally supported on each side of said carriage and having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms de pending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers connected to and swingably supported by said pins between said rockers and said arms and depending therebetween, threads formed on said levers and engaging said arms and adapted to move said arms and jaws inwardly when said levers are swung forwardly with respect to said carriage, actuating bars connected to the levers on each side of said carriage, stops positioned to enact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers forwardly and to thereafter apply an erecting force to said rockers, and coacting with said rockers at the end of the advancing stroke of said carriage to collapse said rocker to inclined position.

17. A sheet transfer device comprising, a carriage reciprocable between two stations, rockers pivotally supported on each side of said carriage and having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers connected to and swingably supported by said pins between said rockers and said arms and depending therebetween,

threads formed on said levers and engaging, and said rockers and adapted to move said arms and jaws inwardly when said levers are swung forwardly with respect to said carriage, actuating bars connected to the levers on each side of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers forwardly and to thereafter apply an erecting force to said rockers, and coacting with said rockers at the end of the advancing stroke of said carriage to collapse said rocker to inclined position.

18. A sheet transfer device comprising, a carriage reciprocable between two stations, rockers pivotally supported on each side of said carriage and having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers secured to and swingably supported by said pins between said rockers and said arms, coacting threads formed on said pins and arms and said rockers and adapted to move said arms and jaws inwardly when the levers are swung forwardly, actuating bars connected to the levers on each side of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers to engage the lifts of said cam surfaces and to thereafter apply an erecting force to said rockers, projections located at longitudinally spaced points on the forward ends of said carriage, carriage tilting arms having fixed pivotal supports at the forward end of the travel of said carriage, said tilting arms having slots formed therein adapted to receive and tilt said projections, 21 release stop engageahle with said rockers in the elevated and tilted positions thereof to return the rockers to inclined position relative to said carriage, and means connected to tilt said tilt arms.

19, A sheet transfer device comprising, a carriage reciprocable between two stations, rockers pivotally supported on each side of said carriage and having angularly disposed surfaces engageable with said carriage to support said rockers alternatively in upright and rearwardly inclined positions, pins projecting inwardly from the swinging ends of said rockers, jaw supporting arms depending from the inner ends of said pins and having inwardly facing jaws on their lower ends, levers secured to and swingably supported by said pins between said rockers and said arms, coacting threads formed on said pins and arms and said rockers and adapted to move said arms and jaws inwardly when the levers are swung forwardly, actuating bars connected to the levers on each side of said carriage, stops positioned to coact with said actuating bars at the end of the retracting stroke of said carriage to swing said levers to engage the lifts of said cam surfaces and to thereafter apply an erecting force to said rockers, projections located at longitudinally spaced points on the forward ends of said carriage, carriage tilting arms having fixed pivotal supports at the forward end of the travel of said carriage, said tilting arms having slots formed therein adapted to receive and tilt said projections, and means connected to tilt said tilt arms.

20. Ina sheet transfer device having a carriage re ciprocable between two work stations, rockers pivotally supported on said carriage on opposite sides thereof, inwardly and oppositely facing jaws relatively pivotally supported from swingable portions of said rockers to be moved by the rockers between raised and lowered positions relative to said carriage, said jaws being movable relative to said rockers inwardly and outwardly relative to said carriage, means for moving said jaws inwardly and outwardly with respect to said rockers, and other means connected to move said first means in response to movement of said carriage, said other means being adapted to move said rockers to raised position after said jaws have been moved inwardly.

21. In a sheet transfer device having a carriage reciprocable between two work stations, rockers pivotally supported on said carriage on opposite sides thereof, inwardly and oppositely facing jaws relatively pivotally supported from swingable portions of said rockers to he moved by the rockers between raised and lowered positions relative to said carriage, said jaws being movable relative to said rockers inwardly and outwardly relative to said carriage, means for moving said jaws inwardly and outwardly with respect to said rockers, and other means connected to move said first means in response to movement of said carriage.

References Cited in the file of this patent UNITED STATES PATENTS 1,343,648 Smith June 15, 1920 2,438,896 Bowen et al. Apr. 6, 1948 2,525,572 Woody et al. Oct. 10, 1950 2,598,222 Cahners May 27, 1952 

